Patrick Troughton took over from William Hartnell who fell ill during the filming of the series. His character was more of a clown character and played the role for three years.

Patrick's Doctor displayed considerable knowledge and experience through his travels and, to an extent, he gained some control of the TARDIS.

In his first story, The Power of the Daleks, which sadly, does not exist except in audio form, the Doctor magically regenerates, to the astonishment and scepticism of his current companions, Ben and Polly and foils a plan by the Daleks to exterminate all humans on the planet Vulcan.

In The Highlanders, the Doctor encounters Jamie, a companion who stays with him until his last story, The War Games. Like the first Doctor, he encounters many aliens, the Daleks and the Cybermen plus Ice Warriors and the Yeti are introduced.

It is the second Yeti story, The Web of Fear that the Doctor encounters Colonel Lethbridge-Stewart for the first time, who, later promoted to the rank of Brigadier, helps the Doctor, Jamie and Zoe foil a plan by the Cybermen to invade Earth with the help of Tobias Vaughn in the Invasion.

The War Games was Patricks last story and is a 10 parter, we first discover the origins of the Doctor, we see his home planet for the first time and meet the Time Lords, the race of which the Doctor is a member. It is in this story that he is charged with interfering with the affairs of lesser species and is exiled to Earth in the late 20th century with a change of appearance.

His companions, Jamie and Zoe, are returned to their respective homes, with their memories erased of the time they spent with the Doctor.

Only six of Patricks stories remain on video format and the rest are missing from the BBC Archives

Patrick appeared in the Five Doctors and with the Sixth Doctor in the story The Two Doctors, his last Doctor Who appearance before his death.